Catalytic process for copolymerizing epoxy compounds with carbon dioxide

ABSTRACT

A catalyst composition and a process for preparing same comprising the reaction product of (a) an organo-metallic compound having the general formula R&#39;nM, wherein n is an integer, at least one R&#39; is an alkyl group, an alicyclic group, or halogen, hydroxy or alkoxy derivatives thereof, or hydrogen, the remaining R&#39; groups are alkyl groups, alicyclic groups, alkaryl groups, aralkyl groups, aryl groups, or halogen, hydroxy or alkoxy derivatives thereof, and M is a metal of Group II or Group III of the periodic Table, (b) a co-catalyst component which is sulfur or a compound containing active hydrogen atoms, and (c) carbon dioxide. The catalyst composition is used in preparing copolymers of epoxy compounds with carbon dioxide.

This is a divisional, of application Ser. No. 380,222, filed July 18,1973, now U.S. Pat. No. 3,900,424.

The present invention relates to the copolymerization of epoxy compoundswith carbon dioxide, and more particularly, to an improved catalyst anda process for preparing same for use in copolymerizing epoxy compoundswith carbon dioxide.

U.S. Pat. No. 3,585,168, in which one of the inventors of the presentinvention was a co-inventor, discloses a catalyst for copolymerizingepoxy compounds with carbon dioxide, which consists of organic compoundsof metals of Group II or Group III of the Periodic Table and aco-catalyst having an active hydrogen atom, such as water, alcohol orketone. This copolymerization catalyst can be prepared by reacting theorganometallic compound component with the co-catalyst component in thepresence of a solvent in a reaction vessel. However, it takes a longtime to copolymerize epoxy compounds with carbon dioxide in the presenceof the above mentioned catalyst, and the yield of the resultingcopolymer is low. Further, the above mentioned catalyst has adisadvantage in that it does not have a high selectivity for producing acopolymer having an alternating structure and, accordingly, the contentof alternating copolymer in the resulting products is low.

It is therefore an object of the present invention to provide a catalystfor copolymerizing epoxy compounds with carbon dioxide, which exhibitsincreased activity in such copolymerization reactions and which resultsin increased yields of copolymer product.

Another object of the invention is to provide a catalyst forcopolymerizing epoxy compounds with carbon dioxide, which is highlyselective in producing a copolymer having an alternating structure andwhich results in increased yields of alternating copolymer in theresulting product.

These and other objects have now herein been attained by providing acatalyst for copolymerizing epoxy compounds with carbon dioxide, whichcomprises a composite catalyst consisting of an organic compound of ametal of Group II or Group III of the Periodic Table and a co-catalystcomponent which is sulfur or a compound containing one or more activehydrogen atoms, treated with carbon dioxide.

The co-catalyst component is sulfur or a compound containing one or moreactive hydrogen atoms. Examplary co-catalysts include: water; saltscontaining water of crystallization selected from halides, nitrates,sulfates, pyrophosphates, phosphates, carbonates, borates, or acetatesof metals, such as magnesium sulfate heptahydrate, magnesium nitratehexahydrate, magnesium phosphate pentahydrate, basic magnesium carbonatepentahydrate, magnesium chloride hexahydrate, magnesium acetatetetrahydrate, zinc sulfate heptahydrate, zinc nitrate hexahydrate,aluminum sulfate octadecahydrate, aluminum nitrate nonahydrate, cadmiumacetate dihydrate, calcium iodide hexahydrate, etc.; sulfur; inorganicacids such as hydrogen sulfide, hydrogen polysulfides, etc.; mono- orpoly-alcohols such as methanol, 1,4-butane diol, trimethylol propane,pentaerythritol, etc.; ketone compounds such as acetone, methyl ethylketone, acetylacetone, etc.; aldehyde compounds such as acetaldehyde,propyl aldehyde, etc.; organic acids such as oxalic acid, isophthalicacid, etc.; polyamines such as piperazine, ethylenediamine,hexamethylenediamine, etc.; primary mono-amines such as ethylamine,propyl amine, aniline, etc.; ammonia; hydrazines; esters or amides suchas dimethyl malonate, acetamide, etc.; nitrile compounds such asacetonitrile, propionitrile, etc.; nitro compounds containing activehydrogen such as nitromethane, nitroethane, etc.; phenolic compoundssuch as resorcin, hydroquinone, aminophenol, novolac resins, etc. Thesecompounds can be used independently or in combination.

The organometallic compounds used as a catalyst component may becompounds having the general formula R'nM wherein n is an integer andwherein at least one R' is selected from the group consisting of analkyl group, an alicyclic group and halogen, hydroxy and alkoxyderivatives thereof, and hydrogen, and the remaining R' groups may beselected from the group consisting of alkyl groups, alicyclic groups,alkaryl groups, aralkyl groups, aryl groups and halogen, hydroxy andalkoxy derivatives thereof. M is a metal element selected from the groupof metal elements in Groups II and III of the Periodic Table such aszinc, calcium, magnesium, cadmium, aluminum, etc. Examples of typicalorganometallic compounds used in the process of this invention includedialkylzinc, tetralkylzinccalcium, dialkylmagnesium, dialkylcadmium,trialkylaluminum, dialkylaluminum mono-halide, alkylaluminumsesquihalide, dialkylaluminum monohydride, etc. Among these compounds,organozinc compounds, organomagnesium compounds and organoaluminumcompounds are especially preferable.

According to the present invention, the catalyst for copolymerizingepoxy compounds and carbon dioxide can be prepared from theseorganometallic compounds and co-catalyst components under the pressureof carbon dioxide gas. That is to say, organometallic compounds arebrought into contact with sulfur or active hydrogen compounds in theatmosphere of an inert gas such as nitrogen, argon, helium, etc. orcarbon dioxide. Gaseous, liquid or solid carbon dioxide, whose amount isequimolar to or more than the amount of organometallic compounds, isadded to the inert gas atmosphere so that when gasified at roomtemperature, the carbon dioxide forms a system having generally apressure of about 5 to 50 kg/cm². The resulting reaction system istreated under agitation at room temperature to 300°C for 0.1 to 100hours, preferably at 50°C to 250°C for 0.2 to 60 hours and morepreferably at 100°C to 200°C for 0.5 to 40 hours. The catalyst of thepresent invention can be also prepared by adding predeterminedco-catalyst components to organometallic compounds preliminarilypreserved in a system under the pressure of carbon dioxide at roomtemperature to about 150°C, and subjecting the resulting mixture to thesame treatment as above. It is also possible to prepare the catalyst ofthe present invention by reacting organometallic compounds withco-catalyst components at room temperature to about 150°C for 150 hoursor shorter period in the absence of carbon dioxide, and subjecting theresulting product to the same treatment as above in the presence ofcarbon dioxide.

The molar ratio of co-catalyst components to organometallic compounds isabout 0.1 to 5.0, generally 0.3 to 2.0. The molar ratio of the compositecatalyst may vary depending upon the selected organometallic compound,the selected co-catalyst or a combination thereof, the epoxide to becopolymerized and other conditions. The catalyst of the presentinvention can be prepared without using solvent, but, in general, it ispreferable and safe to prepare the catalyst in solvents which are alsoused as polymerization reaction solvents.

Any inert organic solvent may be used as the solvent in the presentinvention, including aliphatic hydrocarbons, aromatic hydrocarbons,halogenated hydrocarbons, ethers, esters, carbonates, etc. Specificexamples of suitable solvents are n-hexane, cyclohexane, benzene,toluene, ethylene dichloride, diethyl ether, ethyl isopropyl ether,tetrahydrofuran, dioxane, ethylene carbonate or mixtures thereof. Theactivity of the catalyst of the present invention depends upon the kindof solvent employed. It is preferable to prepare the catalyst in thepresence of ethers such as dioxane, diethylether or tetrahydrofuran asthe solvent to obtain the copolymer in good yield.

Epoxy compounds are copolymerized with carbon dioxide by theconventional method in the presence of the catalyst prepared accordingto the present invention. Examples of epoxy compounds which may beemployed as a co-monomer are ethylene oxide, propylene oxide, 1-buteneoxide, 2-butene oxide, isobutylene oxide, butadiene monoxide, butadienedioxide, styrene oxide, cyclohexene oxide, cyclopentene oxide,1,1-diphenyl ethylene oxide, stilbene oxide, glycidyl methacrylate,methyl glycidyl ether, phenyl glycidyl ether, vinyl cyclohexene oxide,epihalohydrin, dihydronaphthalene oxide, dodecene oxide and mixturesthereof.

In the copolymerization reaction, in general, a catalyst concentration(based on organometallic compounds) in the range of from about 0.001 andlower to about 20 mole percent based upon the epoxide monomer issuitable. A catalyst concentration in the range of from about 0.01 toabout 10 mole percent is preferred. With the increase of the molar ratioof the catalyst, the rate of the copolymerization reaction alsoincreases. However, it is not economically preferable to use anexcessive amount of the catalyst.

Copolymerization between epoxy compounds and carbon dioxide is carriedout as follows: Carbon dioxide gas is added to a reaction vesselcontaining catalyst or catalyst solution and epoxy compounds, and theresulting mixture is copolymerized at the reaction temperature of 0°C to150°C, preferably at room temperature to about 70°C under normal or highpressure. The copolymerization reaction may be carried out in thepresence of an inert liquid organic solvent. Suitable inert solvents forthe copolymerization are, for example, hydrocarbons including aliphaticand cycloaliphatic hydrocarbons such as n-hexane, cyclohexane,n-heptane, petroleum ether, and the like, aromatic hydrocarbons such asbenzene, toluene, and the like, oxygen containing solvents, particularlyethers, such as dioxane, tetrahydrofuran, diethyl ether, diisopropylether and the like, halogenated hydrocarbons such as methylenedichloride, chlorobenzene, and the like, and mixtures thereof.

After the completion of the copolymerization reaction, the reactionmixture is treated as follows: When ethylene oxide is used as the epoxycompound, the reaction mixture is placed in dilute hydrochloric acid toprecipitate the resulting copolymer. When the precipitated product iswashed with water and dried, a water-insoluble rubber-like elasticcopolymer is obtained which is different from either a homopolymer ofethylene oxide or a copolymer whose principal component is ethyleneoxide. To purify this copolymer, it is dissolved in solvents which candissolve such copolymer such as chloroform, dichloromethane, etc., theresulting copolymer solution is washed with dilute hydrochloric acid andthen water, and the washed solution is poured into acetone toprecipitate a substantially alternating copolymer. Polyethylenecarbonate, which is an alternating copolymer between ethylene oxide andcarbon dioxide, is insoluble in acetone. Therefore, when polyethylenecarbonate is precipitated in acetone, such alternating copolymer isseparated from the other products present in the mixture includingacetone-soluble polymers and lower molecular products. On the otherhand, from the hydrochloric acid solution and the wash water used toprecipitate the copolymer, water-soluble products can be recovered byextraction with chloroform followed by evaporation to dryness. Whenepoxy compounds other than ethylene oxide are used, the reaction mixtureis dissolved in a solvent such as chloroform, dichloromethane, benzene,etc., and the resulting solution is washed with aqueous hydrochloricacid and then water. Thereafter, the solution is poured in methanol toisolate methanol-insoluble products from methanol-soluble products.

It is confirmed by the absorption bands of carbonate bond at 1,750 cm⁻ ¹and 1,250 cm⁻ ¹ in infrared absorption spectrum that all the resultingproducts are copolymers. It was also confirmed by the elemental analysisthat epoxy compounds were copolymerized with carbon dioxide. The contentof in-chain carbonate groups within the resulting product is dependentupon the kinds of epoxide monomers and copolymerization conditions.

One effect of the catalyst according to the present invention is that itgives high activity to composition systems consisting of organometalliccompounds and co-catalyst components which have no activity forcopolymerization reactions between epoxy compounds and carbon dioxide,and further that it increases the activity of the conventional activecatalyst system consisting of organometallic compounds and water,primary amine or resorcin, etc. A second effect of the catalyst of thepresent invention is that, compared with the conventional methods, theresulting copolymer, especially water- or methanol-insoluble copolymers,can be prepared in markedly higher yield, and alternating copolymers canbe also obtained in markedly higher yield. These effects of the presentinvention will be apparent from comparison between the followingexamples and references.

As mentioned above, the catalyst of the present invention has higheractivity than known catalysts prepared by the conventional method. Thecatalyst of the present invention also has excellent properties toenhance the yield of the resulting copolymer and has a good selectivityin the copolymerization reaction to produce an alternating copolymer.The catalyst of the present invention has the above mentioned excellentproperties, because it is prepared by treating composite catalystsconsisting of organometallic compounds and sulfur or active hydrogencompounds with carbon dioxide gas. Therefore, from an industrialstandpoint, the present invention is very valuable, providing a catalysthaving high activity for copolymerizing epoxy compounds with carbondioxide.

The present invention will be explained by the following examples.

EXAMPLE 1

170 ml. of dioxane and 9.8 g. (0.08 mole) of diethylzinc were placed ina 500 ml. pressure reaction vessel in which air was replaced bynitrogen. 1.37 g. (molar ratio to diethylzinc: 0.95) of water were addedquickly to the resulting solution in the reaction vessel underagitation. The reaction vessel was tightly stoppered and carbon dioxidegas was introduced therein to a pressure of 20 kg/cm². The reactionvessel was heated at 130°C for 3 hours under agitation. Thereafter, thereaction vessel was cooled and then opened to lower its inner pressureto normal pressure to obtain the catalyst solution.

A copolymerization reaction was performed as follows: 44 g. (1 mole) ofethylene oxide were added to the resulting catalyst solution, and thereaction vessel was tightly stoppered again. 130 g. of carbon dioxidegas were introduced into the reaction vessel under agitation, and thevessel was heated at 50°C for 24 hours under agitation. Then, thereaction vessel was opened to lower its inner pressure to normalpressure. The obtained reaction mixture was precipitated into ahydrochloric acid solution. When the precipitated product was washedwith water and dried, 41 g. of water-insoluble rubber-like elastomerwere obtained. On the other hand, 19.2 g. of water-soluble product wereobtained from the hydrochloric acid solution and wash water byextraction with chloroform followed by evaporation to dryness.

The resulting water-insoluble product was dissolved in chloroform, andwashed with dilute hydrochloric acid and then with water. Afterward theresulting chloroform solution was poured into acetone to precipitate anacetone-insoluble copolymer. As a result, 35 g. of purified whiteelastomer (intrinsic viscosity: 0.65 dl/g at 30°C in dioxane wereobtained. This copolymer was confirmed to be substantially analternating copolymer by the following. The resulting copolymer gaveinfrared absorption spectrum in which strong absorption bandscharacteristic of carbonate bond were observed at 1,750, 1,200, 1,300and 785 cm⁻ ¹. In the above infrared absorption spectrum, no absorptionband of polyether was observed at about 1,100 cm⁻ ¹. The elementalanalytic value of the copolymer was identical to the theoretical valueof the alternating copolymer consisting of ethylene oxide and carbondioxide, as given below.

Elemental analytic value: C:40.99%, H:5.20%. Theoretical value ofalternating copolymer: C:40.92%, H:4.58%.

Reference 1 (Conventional method)

170 ml. of dioxane and 9.8 g. (0.08 mole) of diethylzinc were placed ina 500 ml. pressure reaction vessel in which air was displaced bynitrogen. 1.37 g. (molar ratio to diethylzinc: 0.95) of water were addedto the resulting solution in the reaction vessel. As a result, acatalyst solution was obtained.

The same copolymerization procedure as in Example 1 was repeated in thepresence of the resulting catalyst solution. The resulting reactionmixture was precipitated into dilute hydrochloric acid. When theprecipitated product was washed with water and dried, 29 g. ofwater-insoluble rubber-like elastomer were obtained. On the other hand,15 g. of water-soluble product were obtained from the hydrochloric acidsolution and wash water by extraction with chloroform followed byevaporation to dryness.

EXAMPLE 2

100 ml. of dioxane and 9.8 g. (0.08 mole) of diethylzinc were placed ina 500 ml. pressure reaction vessel in which air was displaced bynitrogen. 1.37 g. (molar ratio to diethylzinc: 0.95) of water werequickly added to the resulting solution in the reaction vessel. Thencarbon dioxide gas was introduced thereinto to a pressure of 10 kg/cm².The reaction vessel was heated at 125° to 136°C for 16 hours underagitation. Thereafter the reaction vessel was cooled to 50°C. As aresult, a catalyst solution was obtained.

A copolymerization reaction was conducted as follows: 97 g. (2.2 moles)of ethylene oxide were added to the resulting catalyst solution underpressure, and carbon dioxide gas was introduced thereinto to a gaugepressure of 40 kg/cm². The resulting reaction system was agitated at50°C for 24 hours. The reaction mixture was then treated in the samemanner as in Example 1. As a result, 70.3 g. of water-insoluble product(intrinsic viscosity:0.65 dl/g at 30°C in dioxane) and 19.4 g. ofwater-soluble product were obtained respectively.

EXAMPLES 3 to 6

64 ml. of dioxane and diethyl zinc and water (as 18% dioxane solution)were placed in a 200 ml. pressure reaction vessel in the flow of carbondioxide gas. The reaction vessel was tightly stoppered, and carbondioxide gas was introduced thereinto to a pressure of 20 kg/cm².Afterward the reaction vessel was heated to 130°C for a predeterminedperiod of time under agitation. After heating was over, the reactionvessel was cooled and then opened to lower its inner pressure to normalpressure. As a result, a catalyst solution was obtained.

The copolymerization reaction was conducted as follows: 34 g. (0.76mole) of ethylene oxide were added to the resulting catalyst solution,and 60 g. of carbon dioxide gas were introduced into the reaction vesselunder pressure, and the resulting reaction system was reacted andtreated as in Example 1. Table 1 shows the experimental results.

                  Table 1                                                         ______________________________________                                        Catalyst prepara-                                                             tion conditions        Product (g)                                            Exam- ZnEt.sub.2 (g)                                                                          H.sub.2 O/ZnEt.sub.2                                                                     Treat-                                                                              Water-in-                                                                            Water-                                ple             molar      ment  soluble                                                                              soluble                               No.             ratio      time  product                                                                              product                                                          (hrs)                                              ______________________________________                                        3     4.01      0.46       3      7.2   9.3                                   4     4.05      0.72       "     18.7   10.3                                  5     3.92      0.81       "     20.6   7.7                                   6     4.00      0.78       0.5    9.8   9.3                                   7     3.84      0.81       12    29.3   9.0                                   8     4.00      0.84       24    30.0   9.5                                   ______________________________________                                    

EXAMPLES 9 to 12

170 ml. of dioxane, 9.8 g. (0.08 mole) of diethylzinc and water wereplaced in a 500 ml pressure reaction vessel. The reaction vessel wastightly stoppered and carbon dioxide was introduced thereinto to apredetermined pressure. The reaction vessel was heated to apredetermined temperature for a predetermined period under agitation.After heating was over, the reaction vessel was cooled and then openedto lower its inner pressure to atmospheric pressure. As a result, acatalyst solution was obtained.

The copolymerization reaction was performed as follows: 44 g. (1.0 mole)of ethylene oxide were added to the resulting catalyst solution, andcarbon dioxide gas was introduced into the reaction vessel to apredetermined pressure. The resulting reaction system was reacted at apredetermined temperature for 24 hours under agitation and treated inthe same manner as in Example 1. Table 2 shows the experimental results.

                                      Table 2                                     __________________________________________________________________________    Catalyst preparation conditions                                                                           polymerization                                                                conditions  Product (g)                           Example                                                                            H.sub.2 O/ZnEt.sub.2                                                                 CO.sub.2                                                                           Tempera-                                                                             Treat-                                                                            CO.sub.2                                                                           Tempera-                                                                             Water-                                                                              Water                           No.  molar ratio                                                                          (kg/cm.sup.2)                                                                      ture (°C)                                                                     ment                                                                              (kg/cm.sup.2)                                                                      ture (°C)                                                                     insoluble                                                                           soluble                                                 time            product                                                                             product                                                 (hrs)                                                 __________________________________________________________________________     9   0.94    5   230    3.0 40   50      9.8  16.4                            10    "     60   200    3.5 60   "      27.8  14.5                            11   1.01   40   150    3.0 50   70     15.2  20.3                            12   0.94   20   130    4.0 30   Room    "     6.3                                                             temper-                                                                       ature                                        __________________________________________________________________________

EXAMPLE 13

170 ml. of dioxane and 9.8 g. (0.08 mole) od diethylzinc were placed ina 500 ml. pressure vessel in which air was displaced by argon. 1.37 g.(molar ratio to diethylzinc: 0.95) of water were added to the resultingsolution in the reaction vessel. Carbon dioxide gas was introduced intothe reaction vessel to a pressure of 20 kg/cm². The resulting solutionwas treated at room temperature for 20 hours under agitation. After thetreatment was over, the reaction vessel was opened to lower its innerpressure to atmospheric pressure. As a result, a catalyst solution wasobtained.

The copolymerization reaction was conducted as follows: 44 g. (1 mole)of ethylene oxide were added to the resulting catalyst solution. Thereaction vessel was tightly stoppered again, and carbon dioxide gas wasintroduced thereinto to a gauge pressure of 23 kg/cm². The resultingreaction system was agitated at 25°C for 24 hours, and the reactionmixture was treated in the same manner as in Example 1. As a result,13.7 g. of acetone-insoluble copolymer were obtained.

EXAMPLE 14

A catalyst solution was obtained in the same manner as in Example 13except that the treatment time was prolonged to 67 hours. Thecopolymerization reaction was also conducted in the same manner as inExample 13, except that the gauge pressure was raised to 24 kg/cm² andthe reaction time was shortened to 6 hours. As a result, 5.0 g. ofacetone-insoluble copolymer were obtained.

Reference 2 (Conventional method)

The same reaction as in Example 13 was conducted except that diethylzincand water were not treated under the pressure of carbon dioxide gas. Thecopolymerization reaction was conducted by adding ethyleneoxide and thencarbon dioxide gas to the resulting catalyst solution. As a result, 1.2g. of acetone-insoluble copolymer were obtained.

EXAMPLES 15 to 17

Metal salt hydrate and a predetermined amount of solvent were placed ina 500 ml pressure reaction vessel in which air was displaced bynitrogen. Diethylzinc was poured into the resulting solution in thereaction vessel under agitation. The reaction vessel was tightlystoppered and carbon dioxide gas was introduced thereinto to a pressureof 30 kg/cm². The resulting solution was treated for 3 hours at roomtemperature or at a predetermined temperature. As a result, a catalystsolution was obtained.

The copolymerization reaction was conducted as follows: 88 g. (2 moles)of ethylene oxide were added to the resulting catalyst solution. Thereaction vessel was tightly stoppered again, and carbon dioxide gas wasintroduced thereinto to a pressure of 50 kg/cm² at 50°C. The reactionmixture was agitated at 50°C for 24 hours. The resulting reactionmixture was placed in dilute hydrochloric acid to precipitate theproduct. When the product was thoroughly washed with water and dried, awaterinsoluble rubber-like product was obtained.

The resulting water-insoluble product was dissolved in chloroform, andthe obtained chloroform solution was poured into acetone to precipitatean acetone-insoluble copolymer. When the precipitated copolymer wasdried in vacuum for 24 hours, a rubberlike elastomer was obtained.

When the infrared absorption spectrum of this rubber-like elastomer wascompared with that of polyethylene carbonate, it was confirmed that therubber-like product was substantially polyethylene carbonate. Table 3shows the experimental results.

                                      Table 3                                     __________________________________________________________________________                                     Water of         Acetone-                                                     crystal-                                                                            Catalyst                                                                            Water-                                                                             insoluble                   Example                                                                            Metal salt  Solvent    Diethyl-                                                                           lization/                                                                           pre-  insol-                                                                             product                     No.  hydrate                zinc diethyl-                                                                            paration                                                                            uble                                                              zinc  tempera-                                                                            product                                                           molar ture °C                                                                      g         Intrinsic                                               ratio)           g    viscosity                                                                     (at 30°C                                                               in                                                                            dioxane)               __________________________________________________________________________    15   Magnesium                                                                            2.8 g                                                                              Dioxane                                                                             170 ml                                                                             10.3 g                                                                             0.96  120   100  97   0.46                        sulfate                           to                                          hepta-                            132                                         hydrate                                                                  16   Zinc sul-                                                                            3.4 g                                                                              Tetra-                                                                              100 ml                                                                             10.6 g                                                                             1.1   Room  28   18   Not deter-                  fate hepta- hydrofuran            tempera-        mined                       hydrate                           ture                                   17   Basic mag-                                                                           6.5 g                                                                              Dioxane                                                                             170 ml                                                                             10.5 g                                                                             0.75  200   46   38   0.54                        nesium car-                                                                   bonate                                                                        penta-                                                                        hydrate                                                                  __________________________________________________________________________

EXAMPLES 18 to 22

Metal salt hydrate and 170 ml. of dioxane were placed in a 500 ml.pressure reaction vessel in which air was displaced by carbon dioxidegas. A predetermined amount of diethylzinc was poured into the resultingsolution in the reaction vessel under agitation. The reaction vessel wastightly stoppered, and carbon dioxide gas was introduced thereinto to apressure of 30 kg/cm². The reaction vessel was heated at 130°C for 3hours under agitation. After heating, the reaction vessel was cooled andthen opened to lower its inner pressure to normal pressure. As a result,a catalyst solution was obtained.

The copolymerization reaction was conducted as follows: 2 moles ofpropylene oxide were added to the resulting catalyst solution. Thereaction vessel was tightly stoppered again, and carbon dioxide gas wasintroduced thereinto to a pressure of 50 kg/cm² at 50°C. The resultingsolution was agitated at 50°C for 24 hours. Thereafter, the reactionvessel was opened to lower its inner pressure to normal pressure. Theresulting product was dissolved in chloroform, and the obtainedchloroform solution was washed with dilute hydrochloric acid and thenwith water. The washed chloroform solution was poured into methanol toprecipitate a methanol-insoluble product.

When the infrared absorption spectrum of the resulting product wascompared with that of polypropylene carbonate, it was confirmed that theproduct was substantially polypropylene carbonate. Table 4 shows theexperimental results.

                                      Table 4                                     __________________________________________________________________________    Example No.                                                                           Metal salt hydrate                                                                        Diethylzinc                                                                         Water of     Methanol-insoluble                                               crystallization/                                                                           product                                                          diethylzinc (molar ratio)                           __________________________________________________________________________    18      Zinc sulfate                                                                              10.6 g                                                                              0.97         144 g                                          heptahydrate                                                                         3.1 g                                                          19      Aluminum                                                                             1.76 g                                                                             6.8 g 0.87          76 g                                          sulfate 18                                                                    hydrate                                                               20      Ditto  3.7 g                                                                              7.0 g 1.77         1.5 g                                  21      Magnesium                                                                            1.7 g                                                                              6.6 g 0.94         26.5g                                          chloride                                                                      hexahydrate                                                           22      Zinc acetate                                                                         8.17g                                                                              10.5 g                                                                              0.38         60.5 g                                         dihydrate                                                             __________________________________________________________________________

EXAMPLE 23

85 ml. of dioxane and 2.8 g. (23 m.moles) of diethylzinc were placed ina 200 ml pressure reaction vessel in which air was displaced by argon.1.27 g. (22 m.moles) of acetone was gradually added to the resultingsolution in the reaction vessel under agitation. The reaction vessel washeated at 80°C to perform reaction for one hour. Afterward carbondioxide gas was introduced into the reaction vessel at 80°C to apressure of 25 kg/cm², and the reaction temperature was raised to 130°C.When the resulting reaction system was reacted for 3 hours under highspeed agitation, pressure in the reaction vessel rose to 35 kg/cm².After the reaction, the reaction vessel was cooled to room temperature,and opened gradually to lower its inner pressure to normal pressure. Asa result, a catalyst solution was obtained.

The copolymerization reaction was conducted as follows: 45 ml. ofethylene oxide cooled to about -60°C were injected by an injector intothe resulting catalyst solution, introducing carbon dioxide gasthereinto, and the reaction vessel was tightly and quickly stoppered.Carbon dioxide gas was introduced into the reaction system to a pressureof 30 kg/cm² at room temperature, and the resulting reaction system wasreacted at 60°C for 24 hours. After the reaction, the reaction vesselwas opened to lower its inner pressure to normal pressure. The resultingreaction mixture was placed in water to stop the reaction, and at thesame time to precipitate part of the product.

The precipitated product was thoroughly washed with dilute hydrochloricacid to remove the residue of the catalyst, and the obtained product waswashed again with water. 22.7 g. of water-insoluble product wereobtained. The resulting water-insoluble product was dissolved inchloroform, and the resulting chloroform solution was poured intoacetone to precipitate an acetone-insoluble copolymer. Afterward theobtained copolymer was dried in vacuum for 24 hours. As a result, 21 g.of acetone-insoluble copolymer were obtained. It was confirmed that theproduct was polyethylene carbonate because in its infrared absorptionspectrum strong absorption bands characteristic of carbonate bond wereobserved at 1,750, 1,200 to 1,300 and 785 cm⁻ ¹, and no absorption bandcharacteristic of polyether was observed at 1,100 cm⁻ ¹.

On the other hand, 7.3 g. of water-soluble product were obtained fromthe aqueous solution by chloroform extraction. It was confirmed by itsinfrared absorption spectrum that the above water-soluble product was amixture of polyether carbonate containing an ether unit and cyclicethylene carbonate.

Reference 3

85 ml. of dioxane and 5.3 g. (43 m.moles) of diethylzinc were placed ina 200 ml. pressure reaction vessel in which air was displaced by argon.2.1 g. (36 m.moles) of acetone were gradually poured into the resultingsolution in the reaction vessel under agitation. The reaction vessel washeated at 80°C to perform reaction for 1 hour. Afterward the reactiontemperature was raised to 130°C without adding carbon dioxide gas to agethe catalyst system for 3 hours. The reaction vessel was cooled to roomtemperature.

The copolymerization reaction was performed as follows: 45 ml. ofsatisfactorily cooled ethylene oxide were injected by an injector intothe resulting catalyst solution under a stream of argon gas, and theprocedure of Example 23 was repeated. As a result, 2.0 g. ofwater-insoluble product and 5.0 g. of water-soluble product wereobtained respectively.

EXAMPLES 24 to 36

The procedure of Example 23 was repeated except that various kinds ofactive hydrogen compounds, as well as sulfur, were used as theco-catalyst components instead of acetone, and various kinds of solventswere used instead of dioxane. Excluding Examples 30 and 34 in which 88g. of ethylene oxide were used, 40 g. of ethylene oxide were used.Excluding Example 34 in which the pressure of carbon dioxide gas was 40kg/cm², the pressure of carbon dioxide gas was 40 to 60 kg/cm². InExamples 29, 30, 33 and 34, the reaction temperature was 50°C. InExample 34, the reaction time was 21.5 hours.

Table 5 shows the experimental results. In Table 5, molar ratio is themolar ratio of active hydrogen compounds to organometallic compounds,catalyst treatment condition I means that the catalyst consisting oforganometallic compounds and compounds having active hydrogen was agedin the absence of carbon dioxide gas, and catalyst treatment conditionII means that the above catalyst was treated in the presence of carbondioxide gas. The water-soluble product of Example 34 was achloroform-insoluble product, and most of the product was theisophthalic acid used as the catalyst.

                                      Table 5                                     __________________________________________________________________________    Example No.                                                                           Solvent   Catalyst   ZnEt.sub.2                                                                         Molar                                                                              Catalyst matura-                                                                        Water-                                                                              Water-                                              (milli-                                                                            Ratio                                                                              tion conditions                                                                         insoluble                                                                           soluble                                             mole)     I    II   product                                                                             product                                                                 (g)   (g)                    __________________________________________________________________________    24      Dioxane                                                                             80 ml                                                                             Nitro-                                                                              0.67g                                                                              23   0.5  100°C,                                                                      130°C                                                                       25    7.9                                      methane              1 hour                                                                             3 hours                           25      n-hexane                                                                           "    "     0.64 "    "    "    "    11.2  5.9                    26      Dioxane                                                                            "    "     0.84 "    "    "    "    6.8   3.6                    27      "    "    Acetal-                                                                             1.90 "    2    80°C                                                                        "    25.6  4.8                                      dehyde               1 hour                                 28      Benzene                                                                            "    Pipera-                                                                             2.10 "    1    "    "    6.4   3.0                                      zine                                                        29      Diethyl                                                                            "    Resor-                                                                              3.15 41   0.7  Room "    59    14.0                           ether     cin                  temper-                                                                       ature                                                                         1 hour                                 30      Dioxane                                                                            170 ml                                                                             Butane                                                                              3.42 45   0.83 "    "    0.5   --                                       diol-1,4                                                    31      "     80 ml                                                                             Acetal-                                                                             2.93 23   1.9  80°C                                                                        120°C                                                                       22.9  5.0                                      dehyde               1 hour                                                                             7.5                                                                           hours                             32      "    "    Acetyl                                                                              3.39 42   0.81 --   130°C                                                                       1.86  4.3                                      acetone                   3 hours                           33      Dioxane                                                                            155 ml                                                                             Oxalic                                                                              4.50 83   0.60 Room 100°C                                                                       2.0   --                                       acid                 temper-                                                                            2 hours                                                                  ature,                                                                        1 hour                                 34      "    111 ml                                                                             Isoph-                                                                              8.24 55   0.90 --   130°C,                                                                      20.0  8.0                                      thalic                    3 hours                                             acid                                                        35      "     80 ml                                                                             Hydrogen                                                                             --  "    0.10 --   "    3.6   2.1                                      sulfide                                                     36      "    "    Sulfur                                                                              6.16 "    3.5  Room "    5.7   7.2                                                           temper-                                                                       ature,                                                                        1 hour                                 __________________________________________________________________________

References 4, 5

Ethylene oxide was copolymerized with carbon dioxide by the same manneras in Reference 1, using various kinds of active hydrogen compoundsinstead of acetone. Table 6 shows the experimental results.

                                      Table 6                                     __________________________________________________________________________    Refer-                                                                            Cocatalyst                                                                          Solvent                                                                            ZnEt.sub.2                                                                         Molar                                                                             Water-                                                                              Water-                                          ence           (milli                                                                             ratio                                                                             insoluble                                                                           soluble                                         No.            mole)    product                                                                             product                                         __________________________________________________________________________    4   Nitro-                                                                              Dioxane                                                                            23   0.50                                                                              5.1 g 1.8 g                                               methane                                                                       0.7 g                                                                     5   Pipera-                                                                             Benzene                                                                            "    0.91                                                                              Trace 9.0 g                                               zine                                                                          2.3 g                                                                     __________________________________________________________________________

EXAMPLE 37

85 ml. of diethylether and 2.8 g. (27 m.moles) of diethylzinc wereplaced in a 200 ml. pressure reaction vessel in which air was displacedby argon. 0.33 g. (5.4 m.moles) of nitromethane and 0.6 g. (11 m.moles)of acetone were successively and gradually poured into the resultingsolution. The catalyst solution was obtained by the same procedure as inExample 23.

The copolymerization reaction was performed as follows: 67 ml. ofpropylene oxide were added into the resulting catalyst solution under acarbon dioxide atmosphere. The vessel was then stoppered, and the carbondioxide was introduced thereinto to a pressure of 30 kg/cm² and stirredat 60°C for 24 hours. The resulting reaction product was precipitated inmethanol containing concentrated hydrochloric acid, rinsed withadditional methanol and dried. The dried product was dissolved inchloroform, and the resulting chloroform solution was shaken welltogether with dilute hydrochloric acid to remove the residue of thecatalyst. Afterward, the obtained solution was washed again with water,and the resulting solution was poured into a large amount of methanol.As a result, 15.2 g. of methanol-insoluble product were obtained. It wasconfirmed that the above product was polypropylene carbonate by itsinfrared absorption spectrum. On the other hand, 3.5 g. ofmethanol-soluble product was recovered from methanol. It was confirmedby its infrared absorption spectrum that the product was a mixture ofpolypropylene ether carbonate containing an ether unit and cyclicpropylene carbonate.

EXAMPLES 38 to 41

Various kinds of epoxy compounds instead of propylene oxide werecopolymerized with carbon dioxide in the same manner as in Example 24.Table 7 shows the experimental results. In these examples, 80 ml. ofsolvent were used.

                                      Table 7                                     __________________________________________________________________________                                                      Methanol-                        Epoxy    Cocatalyst (%)                                                                          ZnEt.sub.2                                                                             Catalyst maturation                                                                            insolu-                          compounds          (milli-                                                                            Molar                                                                             conditions  Solvent                                                                            ble                         Example                                                                            Chemical Acetone                                                                            Acetal-                                                                            mole)                                                                              ratio                product                     No.  name  g       dehyde        I     II         (g)                         __________________________________________________________________________    38   Epichloro-                                                                    hydrin                                                                              40 1.27 --   23   0.95                                                                              100°C,                                                                       150°C                                                                        Dioxane                                                                             0.8                                                         0.5 hour                                                                            5 hours                                39   Cyclo-                                                                        hexane                                                                              50 "    --   "    "   80°C,                                                                        130°C,                                                                       Benzene                                                                             21.0                            oxide                       1 hour                                                                              3 hours                                40   Ethylene                                                                            40 0.97 0.68 "    1.5 "     "     Dioxane                                                                             18.4                            oxide                                                                    41   Glycidyl                                                                      metha-                                                                              19 --   1.10 12.5 2.0 85°C,                                                                        "     Ethylene                                                                            1.0                             crylate                     15 hours    di-                                                                           chloride                         __________________________________________________________________________

EXAMPLES 42 to 49

Solvent, diethylzinc, and water were placed in a 200 ml. pressurereaction vessel under a stream of carbon dioxide gas. A predeterminedamount of carbon dioxide gas was introduced thereinto. The reactionvessel was heated at 135° to 140°C for 5 hours under agitation, andcooled. As a result, a catalyst solution was obtained.

The copolymerization reaction was conducted as follows: A predeterminedamount of various kinds of epoxy compounds were added to the resultingcatalyst solution, a predetermined amount of carbon dioxide gas wasintroduced into the reaction vessel under pressure, and the resultingreaction system was copolymerized at 50°C for 24 hours under agitation.The resulting reaction mixture was dissolved in chloroform, and theresulting chloroform solution was washed with dilute hydrochloric acidand then with water. Afterward, the washed solution was poured intomethanol to precipitate the product. In the infrared absorption spectrumof the product, absorption bands were observed at 1,750, 1200 to 1,300and 785 cm⁻ ¹. Therefore, it was confirmed that various kinds of epoxycompounds copolymerized with carbon dioxide. Table 8 shows theexperimental results.

                                      Table 8                                     __________________________________________________________________________    Example                                                                            Catalyst preparation conditions                                                                      Polymerization conditions                                                                          Methanol-                    No.  Solvent   ZnEt.sub.2                                                                        H.sub.2 O/                                                                             Epoxy compounds  CO.sub.2                                                                          insoluble                                   (mole)                                                                            ZnEt.sub.2                                                                         CO.sub.2                                                                          Chemical         (g) product                      Chemical   ml      (molar                                                                             (g) name     g   Mole    (g)                          name               ratio)                                                     __________________________________________________________________________    42   Benzene                                                                             100 0.08                                                                              0.95 20  Ethylene oxide                                                                         88  2   170 40                           43   Diethyl                                                                       ether "   "   0.94 10  "        "   "   130 21                           44   Benzene                                                                              80 "   "    15  Styrene oxide                                                                          120 1   "   25                           45   Dioxane                                                                             "   0.07                                                                              0.96 "   Isopropylene                                                                           36  0.5 120 4.1                                                      oxide                                             46   n-hexane                                                                            "   "   "    20  Propylene oxide                                                                        116 2   130 13                           47   Dioxane                                                                              85 0.08                                                                              0.95 "   Epichlorohydrin                                                                        185 2   120 7.2                          48   "     100 0.04                                                                              "    "   Cyclohexene                                                                            49  0.5 100 23                           49   Ethylene                                                                      dichloride                                                                          "   0.08                                                                               0.925                                                                             "   Propylene oxide                                                                        58  1   "   28                           __________________________________________________________________________

EXAMPLE 50

100 ml. of dioxane and 2.94 g. (25.8 m.moles) of triethylaluminum wereplaced in a 500 ml. pressure reaction vessel in which air was displacedby argon. 35 ml. of dioxane containing 3.0 g. (34.9 m.moles) ofpiperazine were poured into the resulting solution in the reactionvessel. The resulting solution was treated in the same manner as inExample 23. As a result, a catalyst solution was obtained.

The copolymerization reaction was performed as follows: 30 ml. ofpropylene oxide were poured into the resulting catalyst solution under acarbon dioxide atmosphere, and the resulting solution was reacted at50°C for 36 hours. Afterward, the obtained product was treated in thesame manner as in Example 23. As a result, 1.0 g. of water-insolubleproduct was obtained. The product was confirmed to have a cerbonate unitby infrared spectrum.

Reference 6

A catalyst system consisting of triethylaluminum and piperazine was agedin the same manner as in Example 50 in the absence of carbon dioxide gasat 80°C for 18 hours. Copolymerization was conducted at 50°C for 17hours, but a water-insoluble copolymer was not obtained at all.

EXAMPLE 51

80 ml. of dioxane and 1.37 g. (0.012 mole) of triethylaluminum wereplaced in a 200 ml. pressure reaction vessel in which air was displacedby nitrogen. 0.14 g. (molar ratio to triethylaluminum:0.65) of water wasadded to the resulting solution, and carbon dioxide was introducedthereinto to a pressure of 10 kg/cm². The reaction vessel was heated at130°C for 2 hours under agitation. After heating, the reaction vesselwas cooled and opened to lower its inner pressure to atmosphericpressure. As a result, a catalyst solution was obtained.

The copolymerization reaction was conducted as follows: 10.0 g. (0.72mole) of propylene oxide were added to the resulting catalyst solution.Carbon dioxide was introduced into the reaction vessel to a pressure of20 kg/cm². The resulting product was agitated at 50°C for 10 hours. Theresulting reaction mixture was dissolved in benzene, and the resultingbenzene solution was washed with dilute hydrochloric acid and then withwater. When the washed solution was evaporated to dryness, 6.0 g. ofproduct were obtained. In the infrared absorption spectrum, anabsorption band characteristic of carbonate bond at 1,750 cm⁻ ¹ wasobserved. Therefore, it was confirmed that the product was a copolymerof propylene oxide and carbon dioxide.

EXAMPLE 52

A diethyl ether solution containing 6 m.moles of diethylmagnesium and0.52 g. (6 m.moles) of anhydrous piperazine were aged in 70 ml. oftetrahydrofuran at room temperature for 30 minutes under a nitrogenatmosphere. Afterward the resulting catalyst solution was transferred toa 200 ml. pressure reaction vessel. The catalyst solution was aged at70°C for 1 hour, and then carbon dioxide gas was introduced into thereaction vessel to a pressure of 25 kg/cm² at 70°C. Thereafter, thevessel was heated to 120°C for 3 hours. As a result, a catalyst solutionwas obtained.

The copolymerization reaction was conducted as follows: 40 ml. ofpropylene oxide were injected by an injector into the resulting catalystsolution in the flow of carbon dioxide gas. Carbon dioxide gas wasintroduced into the reaction vessel at room temperature to a pressure of30 kg/cm², and the resulting reaction system was copolymerized at 50°Cfor 40 hours. Afterward the resulting reaction mixture was poured inmethanol containing concentrated hydrochloric acid to stop thecopolymerization reaction. Precipitated product was dissolved inbenzene, and the resulting benzene solution was well washed with dilutehydrochloric acid to remove the residue of catalyst and then subjectedto freeze-drying. As a result, 1.43 g. of solid was obtained. It wasconfirmed by its infrared absorption spectrum that the solid contained acarbonate unit.

EXAMPLE 53

80 ml. of dioxane, 4.78 g. (39 m.moles) of diethylzinc, 0.54 g. (molarratio to diethylzinc:0.78) of water and 0.19 g. (molar ratio todiethylzinc:0.12 ) of methanol were placed in a 200 ml. pressurereaction vessel in which air was displaced by argon. Carbon dioxide gaswas introduced into the reaction vessel to a pressure of 5.0 kg/cm² atroom temperature, and the vessel was heated at 130°C for 3 hours underagitation. As a result, a catalyst solution was obtained.

The copolymerization reaction was conducted as follows: 50 ml. ofethylene oxide were added to the resulting catalyst solution. Carbondioxide gas was introduced into the reaction vessel to a pressure of 30kg/cm² at room temperature, and the copolymerization reaction wasperformed at 50°C for 20 hours. When the resulting copolymer was treatedin the same manner as in Example 23, 25.6 g. of water-insoluble productand 12.8 g. of water-soluble product were obtained respectively.

What is claimed is:
 1. A process for producing a copolymer of an epoxycompound with carbon dioxide, comprising copolymerizing an epoxycompound with carbon dioxide in the presence of a catalyst compositioncomprising the reaction product of (a) an organo-metallic compoundhaving the general formula R'nM, wherein n is 2 or 3, at least one R' isselected from the group consisting of an alkyl group, an alicyclic groupand halogen, hydroxy and alkoxy derivatives thereof, and hydrogen, theremaining R' groups are selected from the group consisting of alkylgroups, alicyclic groups, alkaryl groups, aralkyl groups, aryl groupsand halogen, hydroxy and alkoxy derivatives thereof, and M is a metalelement selected from the group consisting of those metal elements inGroups II and III of the Periodic Table, (b) at least one co-catalystcomponent selected from the group consisting of sulfur and compoundscontaining one or more active hydrogen atoms in a molar ratio to theorgano-metallic compound within the range of from about 0.1 to about5.0, and (c) carbon dioxide gas under a pressure at room temperature offrom about 5 to about 50 kg/cm² and in a molar ratio to theorgano-metallic compound of at least 1, said reaction product havingbeen obtained by reacting together said reactants at a temperaturebetween room temperature and about 300°C for a time of from about 0.1 toabout 100 hours, the copolymerization being carried out at a temperaturewithin the range of from about 0°C to about 150°C.
 2. The process ofclaim 1 wherein the copolymerization is carried out at a temperature ofbetween room temperature and about 70°C.
 3. The process of claim 1wherein the organometallic compound is present in an amount within therange of from about 0.001 to about 20 mole percent based upon the epoxycompound.
 4. The process of claim 3 wherein the organometallic compoundis present in an amount within the range of from about 0.01 to about 10mole percent based upon the epoxy compound.
 5. The process of claim 1wherein the molar ratio of the co-catalyst component to theorganometallic compound is within the range of from about 0.3 to about2.0.
 6. The process of claim 1 wherein M is a metal element selectedfrom the group consisting of zinc, magnesium and aluminum.
 7. Theprocess of claim 1 wherein said organo-metallic compound is selectedfrom the group consisting of dialkylzinc, dialkylmagnesium andtrialkylaluminum.